Abstract The development of implantable high channel electronics interfacing with the central and peripheral nervous system has been a continuing effort for decades covering a wide range of applications. Reliable and clinically proven high channel solutions with hermetic encapsulation of the electronics that would be suitable for the use in a Cochlear or auditory nerve have so far not been demonstrated. The project aims to develop and translate a novel clinical high (60-128) channel implantable programmable stimulator (IPS) for use in Cochlear (CI) and auditory nerve (ANI) implants to expand the useable parameter space (electrode count, tonal range, lower stimulation threshold) far beyond current limits. In this project we will evaluate performance, biocompatibility and safety of a new chronically implantable can and programmable stimulator with high channel feedthrough and assembly for the use in a high channel cochlear and auditory nerve implant that uses the high-density Utah Slant Electrode Array (HD-USEA). The HD-USEA is used as penetrating auditory nerve electrode in a new type of intracranial auditory prosthesis that targets the auditory nerve en route to the brainstem in order to substantially improve hearing performance over the current standard of care, the cochlear implant (CI) (NIH 1UG3NS107688-01). Clinical feasibility and value in human subjects will be demonstrated in a new high channel auditory prosthesis being developed for use in human subjects under an existing UG3/UH3 grant. The current approach is however limited in the ability to use the potentially far higher electrode channel count and subsequent tonal range and resolution due to the limited channel count (12) of the conventional (MED-EL Synchrony) CI stimulator. While this approach is a strength of the UG3/UH3 project that combines existing clinically proven products into one new system as the fastest and lowest risk path towards first in human demonstration, it falls short in using the unique capabilities of the HD- USEA architecture or other higher channel CI electrodes.